f\  n.7!/-S> 


U.  S.  DEPARTMENT   OF  AGRICULTURE, 

BUREAU  OF  PLANT   INDUSTRY     Circular   So.   13. 

B.  T.  G  \l.l."\\  AY    Chief  of  Bureau. 


THE  WORK  OF  THE  SAX  ANTONIO 
EXPERIMENT  FARM  IX  L90T. 


FRANK   B.   HEADLEY,  Scientific  Assistant, 

\NI) 

STEPHEN  II.  HASTINGS,  Farm  Superintendent, 

Western  Agricultural  Extension 

Investigations. 


.  i  l'i  ;: ;     cir.   13    "^ 


WASHINGTON  :  COVE'..'  .  OTFICE  :  1908 


S.  DEPOSITORY 


BUREAU  OF  PLANT  INDUSTRY. 

Physiologist  and  Pathologi  t,  and  Chief  of  Bureau,  Beverly  T.  Gallowaj . 

Physiologist  and  Pathologist,  and  Assistant  Chief  of  Bureau,   \  1 1  >ert  I".  Woods. 

Laboratory  o)  Plant  Pathology,  Erwin  I    Smith,  Pathologist  in  Charge. 

Investigations  of  Diseases  of  Fruits,  Mertoii  B.  Waite.  Pathologist  in  charge. 

Laboratory  of  Forest  Pathology,  Haven  Metoalf,  Pathologist  in  Charge. 

Cotton  inn/  Truck  Diseases  and  Plant  Disease  Surrey,  William  A.  Orton,  Pathologist  in  Charge. 

Plant  J. Hi  History  Investigations,  Walter  T.  Swingle,  Physiologist  in  Charge. 

Cotton   Breeding  Investigations,  Archibald  D.  Shamel  and  Daniel   N.  Shoemaker,  Physiologists  in 

Ch.i  i 

Tobacco  Investigations,  Archibald   l>   Shamel,  Wightman  W.  Garner,  and  Ernest   II.  Mather 

Charge. 
Corn  Investigations,  Charles  P.  Hartley,  Physiologist  in  Charge. 
Alkali  and  Drought  Resistant  Plant  .Breeding  Investigations,  Thomas  II.  Kearney,   Physiologist   in 

Charge. 
Soil  Bacteriology  ami  Water  Purification  Investigations,  Karl  F.  Kellerman,  Physiologist  in  Charge. 
Bionomic  Invt  ligations  of  Tropicaland  Subtropical  Plants,  Orator  F.  Cook.  Bionomist  in  Charge. 
Drug  and  Poisonous  Plant  Investigations  and  Tea  Culturt  Investigations,  Rodney  II.  True,  Physiologist 

in  Charge. 
Physical  Laboratory.  Lyman  J.  Briggs,  Physicist  in  Charge 

Crop  Technology  and  Fibt  r  Plant  Investigations,  Nathan  A.  Cobb,  Crop  Technologist  in  charge. 
Taxonomic mat  Rangi  Investigations,  Frederick  V.  Coville.  Botanist  in  Charge. 
Farm  Management  Investigations,  William  I    Spillman,  Agriculturist  in  Charge. 
Grain  Investigations.  Mark  Alfred  Carleton.  Cerealist  in  Charge. 
Arlington  Experimental  Farm,  Lee  C.  Corbett,  Horticulturist  in  Charge. 
Vegelablt  Testing  Gardens,  William  W.  Tracy,  sr..  Superintendent. 
Sugar-Bccl  Inn  sligations  Charles  0.  Townsend   Pathologist  in  Charge. 
Western  Agricultural  I  tit  n  ion  Invi  stigation     Carl  S.  Scofield,  Agriculturist  in  Charge. 
Dry-Land  Agriculture  Investigations    E   Channing  Chilcott,  Agriculturist  in  Charge. 
Pomological  Collections,  Gustavus  B   Bracket)    Pomologisl  in  Charge 

Field  Investigations  in  Pomology.  William  A.  Taylor  and  G.  Harold  Powell,  Pomologists  in  Charge. 
Experimental  Gardens  arid  Grounds,  Edward  M    Byrnes  Superintendent 
Foreign  Seed  and  Plant  Introduction,  David  Fairchild    Agricultural  Explorer  in  Charge 
Forage  Crop  I  mi  sligations  Charles  V.  riper,  Agrostologist  in  Ch 
Seed  Laboratory,  Edgar  Brown,  Botanist  in  Charge 
Grain  Standardization,  John  D  Shanahan,  Crop  Technologist  in  Charge. 

Subtropical  Laboratory  and  Garden,  tfiami.Fla.   Ernst   \    Bessej    Patl i  I  in  Charge. 

Plant  Introduction  Garden,  chico,  Cat.,  W    W.  Tracy  jr.,  Assistant  Botanist  m  Charge, 

South   Texa     Caidiit    Urownsrilli     7V/     rdwurill'    Green    Pomologist  in  Chargi 

Farmi  r,    Cooperativt  D<  monstration  War/..  Seaman  A.  Knapp  Special  Igent  in  <  barge. 
Seed  Distribution  (directed  by  Chief  of  Bureau)    Lisle  Mori  •       tan t  in  General  Charge. 


Editor,  i.  i:    Rockwell. 

rln.  i  i  I,  1 1;    lames  E.  Jones. 

[Cir.  13] 
2 


B.  P.  I 

THE  WORK  OF  THE  SAN  ANTONIO  EXPER 
MENT  FARM  IN  l!H)7. 


INTRODUCTION. 

Although  San  Antonio  is  one  of  the  oklesl  cities  in  the  Stal 
Texas,  agriculture  in  it-  vicinity  has  nol  been  continuously  successful 
except  with  irrigation.  To  observers  acquainted  with  semiarid  con 
ditions  in  other  States,  the  amount  of  rainfall,  the  soil,  and  oilier 
natural  conditions  indicate  thai  this  section  should  be  well  adapted  to 
dry  farming.  The  rainfall,  were  it  well  distributed,  would  be  suffi- 
cient for  bountiful  crops,  but  a  large  part  of  the  water  is  lost  through 
surface  run  off,  since  much  of  the  rain  comes  in  violent  storms  and 
due-  not  penetrate  readih  into  the  heav^i  soils  that  are  characteristic 
of  the  region.  Severe  droughts  occurring  at  irregular  intervals  and 
alternating  with  period-  of  excessive  rainfall  have  seriously  hampered 
agricult  ural  de\  elopment. 

The  farms  near  this  city  that  have  irrigation  facilities  produce 
abundant  crops,  showing  that  the  soil  is  not  lacking  in  fertility. 
The  further  extension  of  agriculture  in  Bexar  County  and  surround- 
ing counties  depends  more  than  anything  else  upon  catching  and 
holding  the  rain  thai  falls.  The  >oil  musl  be  tilled  in  such  a  manner 
as  to  permit  the  rapid  absorption  of  the  rain,  and  the  best  methods 
to  prevent  the  loss  of  water  by  evaporation  must  be  used. 

The  San   Antonio  Experiment   Farm  of  the  Bureau  of  Planl    [n 
dn-tr\  was  established  in  order  to  tesl  the  practical  utility  of  various 
tillage  methods,  and  also  for  the  purpose  of  testing  varieties  of  field 


-  nee  .Inly.   1904,  the  Bureau  of  Planl    Industry  lias  been  operating  an  e\ 

perimeut   and  de istrntion   farm   near  San   Antonio,  Tex.     The   farm,   which 

consists  of  l -'•  acres,  is  owned  bj  the  citj  of  San  Antonio  and  its  use  is  given 
to  this  Bureau  withoul  charge.  The  buildings  and  permanent  improvements 
were  furnished  by  local  subscription  through  tin-  Business  Men's  Club  of  San 
Antonio.  The  aim  of  the  Bureau's  work  on  this  farm  lias  been  to  ascertain  and 
demonstrate  the  tillage  methods  besl  suited  to  successful  crop  production  in 
this  region,  which  lies  near  the  western  and  arid  limit  of  the  cotton  belt,  and 
also  i"  experiment  with  new  or  little  known  crops  thai  may  be  suited  to  this 
region.  This  circular  is  iutended  to  give  si  Uriel'  and  popular  statement  of  the 
work  of  the  farm  for  1907.     B.  T.  Galloway,  Physiologist  and  Pathologist  and 

Clw  ttM. 

[Cli 


4  SAN    ANTONIO    EXPERIMENT    FARM. 

crops  and  fruits  in  order  to  determine  those  best  adapted  to  the  cli- 
matic and  soil  conditions  of  this  section.  In  connection  with  these 
variety-testing  experiments  many  trees,  shrubs,  and  field  crops  im- 
ported from  foreign  countries  are  being  grown. 

LINES  OF  WORK  UNDERTAKEN. 

The  following  are  the  most  important  lines  of  work  under  way.  a 
large  part  of  which  is  in  cooperation  with  other  office-  of  the  Bureau 
of  Plant  Industry:  Tillage  experiments,  rotation  experiments,  cul- 
tural experiments  with  cotton,  finding  a  method  of  eradicating  John- 
son grass:  acclimatizing  weevil-resisting  type-  of  cotton,  in  coopera- 
tion with  the  Office  of  Bionomic  Investigations;  tests  of  forage  crops, 
in  cooperation  with  the  Office  of  Forage  Crop  Investigations ;  tests 
of  grain  crops,  in  cooperation  with  the  Office  of  Grain  Investigations; 
investigating  the  cause  of  the  sterility  of  sorghum,  in  cooperation  with 
the  Agronomist  in  Charge  of  Grain-Sorghum  Investigations:  and 
tests  of  horticultural  crops,  in  cooperation  with  the  offices  of  Seed  and 
Plant  Introduction  and  of  Field  Investigations  in  Pomology. 

TILLAGE   EXPERIMENTS. 

The  soils  in  the  vicinity  of  San  Antonio  are  mostly  heavy  clay 
and  so  compact  that  they  absorb  water  very  slowly.  To  make  them 
more  open  and  porous,  several  methods  of  tillage  not  ordinarily 
practiced  by  farmers  are  being  tried.  The  more  important  features 
of  the  method-  tested  last  year  were  dee])  plowing,  plowing  in  early 
autumn  rather  than  in  the  spring,  the  addition  of  manure  or  other 
organic  matter,  and  the  maintenance  of  a  dust  mulch. 

DEEP    PLOWING    AND    M   BSOI1  INC. 

Deep  plowing  and  subsoiling  loosen  the  -oil  to  a  depth  of  1_ 
inches  or  more,  so  that  both  water  and  air  can  easily  enter.  In 
addition  to  catching  more  of  the  rainfall,  the  subsoiled  ground  allows 
a  deeper  and  more  healthy  growth  of  the  root-  of  plants.  In  experi- 
ments with  cotton  and  corn  in  L907  four  plots  of  subsoiled  ground 
yielded  more  in  rvcvy  case  than  an  equal  number  of  plots  not  sub- 
soiled.  A  series  of  moisture  determinations  made  during  the  grow- 
ing season  failed  to  -how  any  appreciable  difference,  however,  in 
tie'  moisture  condition  of  the  two  series  of  plots. 

It  costs  almost  twice  as  much  to  plow  and  subsoil  land  as  it  does 
to  plow  it  alone.  The  results  so  far  obtained  are  not  adequate  to  serve 
as  a  basis  for  an  estimate  as  to  whether  this  increase  in  yield  is  suffi- 
cient to  repay  the  additional  cost  of  subsoiling.  There  is  reason  to 
believe,  however,  that  the  effects  of  subsoiling  may  be  evident  in  crops 
for  several  years. 
[Cir.  13] 


SAN     \N  rONIO    EXPERIMENT    FARM.  5 

I   \];].\    I  All.    PI  uu  i  HG. 

It  has  been  common  experience  in  semiarid  farming  that,  where  it 

can  be  'I early  fall  plowing  gives  better  results  than  plowing  in 

the  spring  immediately  before  planting,  yet  this  practice  is  by  no 
means  generally  followed  in  the  vicinity  of  San  Antonio.  It  takes  an 
extra  amount  of  power  t<>  plow  the  land  when  it  is  hard  and  dry, 
usually  is  in  the  late  summer  after  crops  have  matured,  so  that  the 
temptation  is  strong  to  put  off  plowing  until  the  ground  has  been 
softened  by  rain.  When  rain  falls  on  hard,  unplowed  ground  much 
iih.it  ol'  it  is  lost  l>'\  surface  run-off  than  when  it  falls  on  loose,  plowed 
land.  For  this  reason  fall-plowed  land  usually  shows  a  greater  soil 
moisture  contenl  than  spring-plowed  land. 

In  October,  1907,  a  portion  of  a  field  of  sorghum  was  plowed,  the 
other  part  being  left  unplowed  until  December.  In  the  mean  time 
more  than  7  inches  of  rain  had  fallen,  and  soil  moisture  determina- 
tions made  in  December  showed  that  in  the  first  3  feel  of  the  land 
plowed  in  October  there  was  24.9  per  cent  of  water,  while  the  land 
plowed  in  December  contained  for  the  -a me  depth  22.6  per  cent.  This 
was  a  saving  equivalent  to  Id  inches  of  rain  actually  absorbed  and 
held  as  a  result  of  the  earlier  plow  ing. 

There  are.  of  course,  many  local  factor-  that  must  be  taken  into 
account  in  determining  the  besl  time  to  plow  in  any  region.  The 
important  thing  i-  that  when  the  land  is  not  actually  in  crop  the 
surface  should  be  kept  in  the  best  possible  condition  to  absorb  and 
retain  any  rain  that  fall-.  Tin-  i-  not  merely  good  farm  practice;  it 
i-  absolutely  necessary  to  insure  crop  production  in  the  San  Antonio 
region. 

MANURING. 

Either  the  application  of  barnyard  manure  or  the  plowing  under 
of  green  crop-,  besides  increasing  the  -oil  fertility,  has  a  tendency 
to  loosen  the  soil  aid  to  put  it  into  much  better  condition  for  the 
absorption  and  retention  of  water.  It  i-  true  that  a  heavy  dressing 
of  stable  manure  apparently  dries  out  the  -oil.  particularly  if  the 
manure  i-  coarse.  This  i-  because  such  manure  both  ventilates  the 
-oil  ami  actualh  absorbs  water  from  it.  din-  effect  i-  immediate 
hut  not  permanent.  Although  it  may  dry  out  the  soil  to  some  extent 
at  first,  at  the  same  time  the  manure  put-  it  into  hetier  condition  for 

tin'  absorpti f  moisture.     When  heavy  rain-  fall  upon  manured 

land  it  may  accumulate  more  moisture  than  unmanured  land. 

This  peculiarity  of  manure  to  at  lir-t  dry  out  the  -oil  make-  it  quite 
necessary  in  a  dry  climate  t<>  apph  it  in  the  fall  or  early  winter 
lather  than  in  the  spring.  Bad  effects  from  drought  are  likely  t" 
follow  if  the  manure  he  added  I  nit  a  short  time  he  lure  seeding. 

■ 

[Cli 


SAN    ANTONIO    EXPERIMENT    FARM. 


I  ill      DTJS1     Ml  I .(  II. 


Direct  evaporation  from  the  soil  can  be  checked  by  keeping  the 
upper  2  or  3  inches  of  the  surface  well  cultivated,  so  as  to  form  a  dust 
blanket,  or  dust  mulch.  When  the  ground  is  kept  covered  with  a 
thick  layer  of  dry,  loose  soil,  evaporation  is  slight,  but  when  the  soil 
surface  is  not  kept  dry  and  loose,  evaporation  goes  on  very  rapidly. 
The  tools  required  for  maintaining  the  dust  mulch  are  a  common 
barrow,  a  vveeder,  and  various  form-  of  cultivators.  The  fact  that 
the  -oil  in  the  vicinity  of  San  Antonio  is  heavy,  together  with  the 
comparative  rarity  of  high  winds,  makes  it  possible  to  maintain  an 
effective  dust  mulch  and  to  accumulate  in  the  soil'  enough  moisture 
to  carry  a  crop  to  maturity  even  if  little  rain  falls  during  it-  growth. 

After  the  dust  mulch  has  been  destroyed  by  a  rain,  evaporation 
from  the  supply  of  water  in  the  soil  begins  as  scion  as  the  rain  ceases, 
and  in  cases  where  the  weather  immediately  following  the  rain  is  hot 
and  windy  this  loss  of  moisture  becomes  exceedingly  "Teat.  On  the 
heavy  soils  of  San  Antonio  a  light  rain,  as  for  instance  0.1  to  0.-1 
inch,  reduces  rather  than  increases  the  total  amount  of  soil  water. 
This  is  apparently  due  to  the  fact  that  such  lighl  rain-  are  only  suf- 
ficient to  establish  capillary  connection  between  the  surface  soil  and 
the  moisture  in  the  lower  soil,  and  before  the  surface  is  dry  enough 
to  permit  cultivation  some  of  the  moisture  has  been  drawn  from  the 
supply  below  and  dissipated  into  the  air.  A  rain  of  less  than  0.1 
inch  is  usually  insufficient  to  establish  such  capillary  connection,  and 
is  therefore  harmless.  Even  a  heavy  rain,  mile--  followed  immedi- 
ately by  cultivation  to  renew  the  dust  mulch,  may  result  in  a  reduc- 
tion rather  than  in  an  increase  of  the  amount  of  -oil  moisture.  Such 
a  case  i-  illustrated  by  Tahle  I. 


Table  I. — Soil  moisture  in  mi  orchard  and  <i  cornfield  cultivated  on  June  .',  ami 
■/line  .;.  1907,  respectively,  illustrating  tin   effect  of  early  Ullage  after  ruin. 


Doi>i  h  In  for: . 

Orchard. 

field. 

Moisture,     Moisture, 
May  28.         JuneG 

Moisture, 

May  28 

\l  ii  lure, 

l 

3 

Average- 

Per  a ni .      Pi  i  , 

22.3               22.2 
21.2                   i 
19  6                17.8 

1'ir  cent . 
18  3 

18   I 

i  i  e 

cent. 
:0.o 
18.6 

21.0                20.4 

17.4 

On  May  29,  1.2  inches  of  rain  fell,  which  should  have  raised  the 
moisture  content  of  the  upper  3  feet  of  soil  2.7  per  cent  had  it  all 
been  absorbed.  Seven  day-  after  the  rain,  in  the  absence  of  a  dust 
mulch,  the  moisture  content  of  the  first  3  feet  in  the  orchard  was  0.6 
per  cent   less  than  it  had  been  before  the  rain.     Had  this  held  been 

[Cii\  L3] 


SAK     ANTONIO    EXPERIMENT    FARM.  i 

harrowed  two  or  three  day-  after  the  rain  there  would  have  been  an 
increase  in  the  amount  of  water  in  the  soil  instead  of  an  actual  de- 
crease. In  a  near-bj  field  of  corn  which  was  cultivated  two  days 
earlier  than  the  orchard  there  was  an  increase  of  O.C  per  cent  of 
moisture  over  what  was  in  the  soil  May  28. 

WIXTEK     I'M. I.  VGE. 

Not  only  is  it  important  to  keep  a  well-established  dust  mulch  on 
all  cultivable  land  throughout  the  summer,  but  effective  measures 
should  I"'  taken  in  catch  and  bold  all  the  moisture  possible  that  may 
fall  during  the  winter.  In  cold  climates,  where  the  soil  remains 
frozen,  but  little  tillage  can  be  given.  The  San  Antonio  climate. 
however,  is  comparatively  warm  in  w  inter,  so  that  much  soil  moisture 
may  be  lost  by  evaporation  unless  the  ground  is  harrowed  or  culti- 
vated so  as  to  establish  a  dust  mulch  after  rains. 

The  usual  method  is  to  stir  the  surface  of  the  ground  as  soon  as  it 
can  be  worked  after  each  rain.  Winter  harrowing  of  fallow  land 
maj  seem  to  be  an  expensive  operation,  but  in  this  region  it  is  very 
likely  to  make  the  difference  between  success  and  failure,  and  the  ex- 
pense is  really  not   verj   great  where  proper  tools  are  used. 

Table  II  -how-  the  results  of  soil-moisture  determinations  made  on 
March  12,  1908,  on  two  fields,  one  of  which  was  fall-plowed  and  kept 
well  tilled  throughout  the  winter  and  the  other  plowed  in  February. 
These  plots  bore  the  same  kind  of  a  crop  in  L907,  and  the  moisture 
condition  in  the  autumn  was  probably  alike  in  both.  It  will  be  noted 
that   the  upper   foot  of  soil  of  the  winter-tilled  plot   retained  :'>.  I    per 

cent    re  moisture  than  the  plot   that    was   left    without   cultivation 

until  February. 

Tabu  II.  -Soil  moisture  on  March  I.'.  1908,  in  tico  m  Ids  at  San  Antonio,  Tt  /.. 
om  of  which  irn.s  /ilmriil  during  /In  prcriottx  autumn  and  flic  other  in  tin- 
pt  i ,  i  iiinii  month. 


Full 

plowed 

Held. 


Spring- 
plow  ed 
Held. 


Average 


III. 4 


Rl  I  I   VI  I'  >\    >i|     CROPS. 


There  are  few  subject?  so  much  discussed  in  tlio  agricultural  papers 
and  at  the  same  time  so  little  understood  as  the  rotation  of  crop-.  It 
has  long  been  known  that  continued  use  of  the  land  for  a  single  crop 

[Cir.  13] 


SAX    ANTONIO    EXPERIMKNT    FARM. 


finally  results  in  reduced  yield-,  and  it  is  also  generally  recognized  thai 
alternating  two  or  more  crops  gives  better  results  than  when  but  one 
is  grown  continuously. 

To  find  ilif  rotations  best  suited  to  any  given  agricultural  region  is 
a  very  complex  undertaking  and  one  that  takes  many  years  to  accom- 
plish. To  find  suitable  rotation-  it  is  necessary  to  determine  the  crops 
that  can  be  most  profitably  grown,  the  order  in  which  they  should  fol- 
low each  other,  and  the  tillage  methods  most  successful  in  securing 
high  yield-.  The  effect  of  the  entire  system  of  rotations,  combined 
with  the  best  tillage  methods,  should  be  to  maintain  or  increase  the 
soil  fertility.  Establishing  rotations  in  the  semiarid  regions  is  com- 
plicated by  the  fact  that  they  must  lie  adapted  to  the  conservation  of 
soil  moisture. 

For  successful  farming  in  the  region  of  San  Antonio  not  only  must 
the  best  methods  known  be  used  for  saving  the  soil  moisture,  but  it 
is  also  important  that  proper  rotation  of  crops  be  followed  if  high 
productiveness  is  to  be  maintained.  In  order  to  find  practical  rota- 
tions that  will  keep  the  soil  in  condition  to  give  the  maximum  yields, 
about  forty  rotations  have  been  planned  and  are  now  being  carried  on 
at  the  experiment  farm. 

To  show  the  method  of  procedure  the  following  examples  are  given: 


Rotation  A.              Rotation  B.              RotationC. 

i  lats  and  vetch.       Oats  and  \  etch 

•  lats  and  vetch, 
followed   by 
cowpeas, 

Cot  ton                            Cotton. 

Cotton. 

( 'mil. 

i  "ii.  manured. 

t  '(.in.  manured. 

Tl  will  lie  noticed  that  only  one  factor  is  changed  for  each  rotation. 
Rotations  A  and  B  differ  only  in  the  fact  that  the  corn  is  manured 
in  the  latter.  After  a  series  of  years  the  results  of  the  manuring 
should  be  apparent  on  all  of  the  crops  in  Rotation  1>.  and  the  effect 
of  this  manure  can  he  determined  by  comparing  the  yields  in  15  with 
A.  Likewise,  the  effect  of  the  cowpeas  on  the  yield-  of  the  crops  in 
Rotation  C  can  he  determined  by  comparing  C  with  B. 

In  the  same  way.  by  changing  one  factor  at  a  time  in  the  rotation, 
we  may  compare  the  effects  of  deep  and  shallow  plowing,  of  fall  and 
spring  plowing,  and  may  determine  (he  value  of  disking  and  liie 
effect   of  plowing  under  green  crops. 

The  rotation  experiments  have  been  but  recently  started  and  it  is 
-till  loo  early  to  draw  conclusions  as  to  the  results,  hut  it  seems 
certain  that  (he  differences  in  yield-  will  he  brought  out  more  and 
i  i  i    i  .-,  i 


s\X    ANTONIO    EXPE]  I   \i:.M.  9 

more  distinct h   in  the  years  that  follow,  and  the  rotation-  best  suited 
to  the  region  will  be  shown. 

Ml   rilOOS    "l     PREVENTING    STERI1  in     I  \     SORGHUM. 

Sorghum  is  one  of  the  commonest  forage  crops  grown  in  the 
vicinity  of  San  Antonio,  and  such  varieties  as  milo  and  kafir  thrive 
well  there  and  would  be  profitable  as  grain  crops  were  it  not  for  the 
fact  that  tln'\  can  nol  be  depended  upon  to  produce  seed.  It  has  been 
generally  supposed  thai  unfavorable  weather  conditions  al  flowering 
time  was  the  cause  of  sterility,  which  is  often  complete.  The  true 
explanation  of  this  sterility  was  not  discovered  until  the  season  of 
L907,  when  a  special  study  was  made  of  the  problem  al  a  number  of 
places,  including  the  San  Antonio  Farm.  An  elaborate  series  of  ex 
periments  was  planned,  which  included  planting  sorghums  al  regular 
intervals  during  the  season  and  a  close  study  of  the  weather  con- 
dil  ions  at  Mow  ering  time. 

It  was  found,  however,  that  it  was  nol  the  climate  thai  caused  the 
sterility,  but  that  it  was  due  to  the  activities  of  certain  minute  red- 
bodied  flies  {Diplosis  sorghtcola)  thai  infested  the  sorghum  [leads  al 
the  time  the  flowers  opened.  These  insects  lay  their  eggs  in  the 
blossoms;  from  these  eggs  tiny  maggots  hatch  out,  our  in  each  flower, 
and  during  their  growth  these  maggots  absorb  the  substance  of  the 
newly  formed  seed.  In  fourteen  or  sixteen  day-  after  the  eggs  are 
laid  these  maggots  have,  in  turn,  become  mature  flies.  No  practical 
remedy  has  yel  been  found  for  combating  the  work  of  this  insect, 
although  it  is  quite  possible  to  secure  -<'r>\  by  covering  the  sorghum 
head-  with  paper  bags  before  the  flowers  open. 

Further  investigations  concerning  the  sorghum  midge  are  being 
carried  on  and  it  i-  hoped  that  some  practicable  method  of  combating 
it  max  be  discovered. 

i  i:  \nu    \  I  lo\    i  if    .n  .11  \-o\    GR  \--. 

Johnson  gra  !  dropogon  hah  p<  nsh  Brot.),  which  may  be  either 
a  valuable  forage  crop  or  a  pernicious  weed,  depending  upon  how  it  is 
controlled,  i-  an  important  feature  of  the  agriculture  near  San  An- 
tonio. This  grass  perpetuates  and  spreads  itself  not  only  by  seed 
hut  by  rootsttfeks  sent  oul  beneath  the  surface  of  the  soil.  These  root 
-lock-  are  capable  of  sending  up  a  new  plant  al  each  joint.  It  i-  on 
this   ace, unit    that    the  grass   i-  so  difficult    to  exterminate,  and   any 

For  .i  more  detailed  report  <>n  tins  subject,  see  "The  Sorghum  Midge,"  by 
Onrie'tou  R.  Ball.  "Science."  n.  s.,  vol.  27,  up.  til   115.  January    17.   LOOS. 

r.'i-  another  method  i»f  eradication,  see  Farmers'  Bulletin  No.  279,  entitled 
■■  \    Method   of   Eradicating  Johnson   ■  trass." 

[Clr.  13] 


10  SAX    ANTONIO    EXPERIMENT    FAEM. 

method  of  getting  rid  of  it  must  be  one  that  will  prevent  the  forma- 
tion of  now  rootstocks.  It  has  been  found  by  observing  the  habits  of 
the  plant  that  new  rootstocks  do  not  form  until  the  plant  is  0  or 
8  inches  high  or  is  ready  to  head  out.  It  is  obvious,  therefore,  that 
if  the  plant  is  never  allowed  to  attain  a  greater  development  than  this 
it  must  die  as  soon  as  the  last  joint  of  the  old  rootstock  has  sprouted 
or  decayed. 

In  the  spring  of  100G  work  was  begun  to  eradicate  the  Johnson 
grass  that  wholly  covered  a  large  part  of  the  farm  and  that  occurred 
sporadically  on  the  remainder.  At  first,  attempts  were  made  to  rake 
the  roots  into  windrows  on  the  surface  and  burn  them,  but  this 
method  proved  more  expensive  and  less  effective  than  persistent  cul- 
tivation. It  was  found  that  a  quicker  plan  of  eradication  was  to  cut 
the  grass  off  below  the  surface  of  the  ground  as  often  as  it  attained  a 
height  of  6  or  8  inches. 

In  killing  out  a  meadow,  the  best  results  were  obtained  by  plowing 
the  land  shallowly  in  September  and  sowing  to  winter  oats.  During 
the  winter  while  the  grass  i-  dormant  the  oats  reduce  the  moisture 
content  of  the  -oil.  so  that  in  the  spring  when  they  are  cut  for  hay 
the  ground  is  left  comparatively  dry.  The  resulting  growth  of  the 
Johnson  grass  is  not  so  vigorous  as  on  fields  left  fallow  during  the 
winter  and  is  kept  down  with  greater  ease  by  the  cultivation  follow- 
ing the  removal  of  the  crop. 

In  September,  L906,  a  6-acre  field  of  Johnson  grass  meadow  was 
plowed  1  to  o  inches  deep  with  a  disk  plow.  In  November  the  field 
was  divided  into  two  parts.  A  and  B. 

Field  A  contained  L'  acres  and  was  left  fallow  during  the  winter. 
The  cultivation  required  to  keep  down  the  Johnson  grass  during  the 
months  of  February.  March,  and  April  cost  $10.84  per  acre  for  man 
and  horse  labor,  which  is  rather  too  expensive  for  general  practice. 
In  May,  when  the  eradication  was  nearly  complete,  this  field  was 
sown  to  German  millet. 

Field  B,  containing  1  acres,  was  sown  to  oats  in  November.  In 
the  spring  the  Johnson  grass  grew  very  vigorously  in  Field  A.  hut 
(lie  growth  in  the  oats  in  Field  B  was  weak,  and  but  few  plants  headed 
out  before  harvesting,  which  was  early  in  .May.  The  field  was  plowed 
again  in  dune  at  a  cost  of  $-_'.7:>  per  acre,  but  this  should  not  be 
charged  against  the  cost  id'  eradicating  the  grass,  since  it  left  the  Held 
in  excellent  condition  for  the  following  crop.  The  cos!  of  cultivation 
to  eradicate  the  Johnson  grass  after  plowing  was  only  $1.12  per  acre. 

The    above    treatments    were    equally    efficient    in    eradicating   the 
grass,  but  (he  difference  in  cost   was  entirely  in  favor  of  the  second 
method  given. 
[Cir.  13] 


s\\     VXTONIO    EXPER1  \l  INI     I   \l;  M.  11 

The  most  useful  implement  for  this  work  is  a  2-horse  G-shovel 
cultivator  with  sweep  attachments.  A  -mall  L-horse  cultivator  with 
similar  sweeps  does  a-  good  work  a-  the  large  one,  bul  is  of  course 
more  expensive,  since  one  man  can  not  accomplish  a-  much  in  a  day. 
When  iIm  grass  occurs  only  in  -mall  scattered  spots,  cultivation  of  the 
whole  field  becomes  unnecessary.  These  spots  can  lie  cleaned  up  by 
keeping  the  grass  cut  down  with  a  garden  lioe.  Digging  out  the 
roots  in  such  spots  (a  plan  followed  by  some  farmers)  i-  no  more 
effective  than  cutting  <>!l  the  plants  and  i-  much  more  laborious 
and  expensive. 

In  attempting  in  eradicate  Johnson  grass  by  any  method  the 
work  must  he  thoroughly  done,  for  it'  any  plant-  he  allowed  to 
approach  maturity  all  the  previous  work  is  lost.  Thorough  culti- 
vation will  kill  out  i  he  grass.  Careless  cultivation  makes  it  grow 
more  \  igorously. 

I  Rl  a'-    l  OR    l'  a:  VGE    l\H   GREEN     M  \  \  I   RE. 

There  i  cms  lack  of  suitable  forage  crop-  in  the  region  about 

San  Antonio.     In  the  drier  seasons  not  enough  forage  is  produced  to 
supply  the  local  demand  and  it   becomes  necessary  to  have  supplies 
brought  in  from  outside  sources.     Such  a  condition  i-  both  undesir 
able  ami   unnecessary    and  tend-  to  cripple  the  dairying  and  stock- 
raising  industries,  which  should  flourish  in  this  region. 

Johnson  grass,  sorghum,  and  winter  oat-  are  at  present  the  most 
prominent  and  profitable  forage  crop-  grown.  While  Johnson  grass 
i-  a  profitable  crop  when  properly  handled,  it  i-  a  serious  pest  where 
not  under  control,  and  the  danger  of  scattering  it  by  feeding  is  so 
great  that  it  i-  far  from  being  a  popular  forage  crop. 

Winter  oat-  make  a  very  desirable  (^otl.  hut  do  not  seem  to  he 
ordinarily  profitable  enough  to  induce  farmers  to  raise  a  sufficient 
quantity  to  supply  the  market. 

Sorghum  yield-  well  and  i-  fairly  drought  resistant,  but  it  is  so 
hard  to  cure  thai  farmers  do  not  grow  it  extensively.  A  number  of 
experiments  in  methods  of  planting  sorghum  for  forage  have  been 
tried.  The  results  -how  that  heavier  yield-  are  obtained,  at  least 
in  tht  tir\  year-,  when  the  sorghum  is  drilled  in  row-  far  enough 
apart  to  allow  cultivation.  In  L907  a  field  of  sorghum  -own  in  the 
manner  usually  followed  by  the  San  Antonio  farmer-,  that  i-.  by 
broadcasting  the  seed,  yielded  1.68  tons  per  aire,  while  the  same 
variety  of  sorghum  dialled  in  row-  I  feet  apart  in  an  adjoining  plot 
yielded  '_'.'•»  ton-  of  cured  fodder  per  acre. 

Sorghum  grown  in  drilled  rows  has  (he  disadvantage  ol  producing 
a  coarser  fodder  than  when  -own  broadcast,  hut  in  spite  "I  this  the 

[Clr.  13] 


12  SAX    ANTONIO    EXPERIMENT    FARM. 

tota]  yield  of  digestible  dry  matter  is  much  greater.  "When  the  sor- 
ghum is  to  be  put  on  the  market  a  readier  sale  may  be  found  for 
the  broadcasted  sorghum  on  account  of  its  liner  quality,  but  for  home 
consumption  the  drilled  sorghum  will  be  found  to  be  the  more  profit- 
able crop.  When  drilled,  it  may  be  cut  with  a  corn  binder  and 
shocked  by  hand  in  the  same  manner  as  corn,  so  that  little  difficulty 
is  experienced  in  curing  it. 

.Vetches  are  winter  annuals  that  may  be  grown  alone  or  in  mixture 
with  oats.  There  are  a  few  varieties  that  seem  to  he  adapted  to  San 
Antonio  conditions.  The  scarlet  vetch  (Vicia  fulgens)  is  one  of  the 
most  promising  species  so  far  tried.  It  is  not  certain  yet  that  any 
of  the  vetches  will  prove  profitable  as  a  forage  crop  for  San  Antonio 
conditions,  but  they  will  certainly  be  valuable  in  rotation  as  winter 
annuals  that  will  improve  the  soil  and  yield  at  least  a  small  amount 
of  forage.  No  yield  tests  of  forage  have  yet  been  made,  as  all  the 
better  varieties  under  trial  wTere  allowed  to  mature  in  order  to  save 
the  seed. 

Many  varieties  of  cowpeas  have  been  tried.  Some  of  them  have 
proved  to  be  fairly  drought  resistant  and  their  culture  is  to  be  rec- 
ommended. Cowpeas  not  only  make  a  very  nutritious  hay.  I  nit. 
like  the  vetches,  are  of  value  in  maintaining  soil  fertility.  As  the 
forage  yield  of  eow7peas  is  not  usually  large  they  can  not  lie  recom- 
mended solely  as  a  forage  (Top.  but  rather  as  a  green  manure  crop 
to  be  used  in  the  rotation  for  their  beneficial  effects  upon  the  soil. 
Tin1  varieties  that  did  best  last  year  on  the  experiment  farm  were  the 
Whippoorwill,  Iron,  and  Clay.  Some  especially  drought-resistant 
strains  have  been  selected  from  among  these  varieties  ami  are  being 
li>ro2:>agalcd. 

A  newly  introduced  plant  from  India  known  as  "guar"  (Cya- 
mopis  tetragonoloba)  has  been  found  very  drought  resistant.  It  is 
a  legume,  having  nitrogen  nodules  on  the  roots:  hence.it  will  undoubt- 
edly prove  valuable  in  increasing  the  soil  fertility.  It  can  at  present 
be  recommended  for  planting  only  as  a  green  manure  crop  or  as 
forage  for  sheep,  as  other  kinds  of  stock  do  not  readily  eat  any  of  the 
varieties  so  far  tested. 

Several  varieties  of  clover  have  been  on  trial,  but  so  far  none  have 
proved  to  lie  sufficiently  drought  resistant  to  be  of  value.  Rape  was 
tried  for-two  seasons,  hut  both  times  it  was  killed  out  by  the  harle- 
quin licet  les.  so  that  it  can  not  he  considered  a  success. 

Alfalfa  is  not  a  successful  crop  in  the  vicinity  of  San  Antonio 
when  sown  in  the  ordinary  manner  unless  irrigated.  In  the  spring 
of  1907,  in  cooperation  with  Mr.  Charles  J.  Brand,  of  the  Office  of 
[Cir.  13] 


S  \.\     W  rON  1"    I  XPl  Ki  M  I  .\  [   FARM.  1  3 

Plant  Life  History  [nvestigations,  L.28  acres  were  planted  to  alfalfa 
varieties  in  double-drilled  rows  2  feel  apart,  so  as  to  permit  cultiva 
t ion.  These  varieties  survived  the  severe  droughl  of  the  summer  of 
L907,  and  in  March,  L908,  the  first  cutting  yielded  1,236  pounds  of 
cured  alfalfa  haj  from  the  field,  a  yield  equivalent  to  957  pounds  to 
the  acre.  Adjacent  plots  -own  in  the  ordinary  manner  that  i-.  in 
drills  6  inches  apart  yielded  at  the  same  time  at  the  rate  of  only 
:'.l 8  pounds  to  the  acre. 

This  indicates  that  there  is  a  possibility  of  growing  alfalfa  suc- 
cessfully ncai'  San  Antonio  without  irrigation,  if  ii  be  planted  so  as 
in  permit  intertillage.  Experiments  are  now  under  way  to  determine 
the  i '.<'- 1  practicable  method  of  sowing  this  crop  and  of  keeping  down 
the  weeds  when  the  plants  are  young. 

'  R(  IPS    RAISED    FOB    URA1  N. 

There  is  much   need   for  more  grain  crops  in   the  vicinity  (if  San 

Antonio.     Ai  presenl  nol  ei gh  grain  is  raised  to  supply  the  local 

demand.  '1  here  i-  no  apparent  reason  why  some  varieties  of  grain 
should  not  prove  successful  in  this  region,  for  the  average  rainfall 
i>  decidedly  more  than  thai  of  some  of  the  more  important  grain- 
producing  regions.  Ii  is  possible  that  the  common  failure  of  grain 
crops  may  he  due  to  disease  and  not  to  the  lack  of  moisture.  In  such 
a  case  it  will  become  necessary  to  find  and  use  the  more  disease-resist- 
ing varieties.  Tests  are  now  being  made  of  a  number  of  varietii 
winter  wheat,  oats,  barley,  and  rye,  and  these  crops  are  being  watched 
carefulh  to  determine  whether  or  nol  it  is  disease  or  insect  pests  that 
cause  the  comparative  sterility  and  consequent  low  yield-.  No  recom- 
mendation of  varieties  can  yet  he  made. 

A-  ha-  already  been  pointed  out,  the  use  of  varieties  of  sorghiun 
for  main  production  i-  not  now  possible,  owing  to  the  ravages  of  the 
sorghum  midge. 

CULTURAL    EXPERIMENTS    Willi    COTTON. 

Two  line-  of  work  are  being  carried  on  with  cotton.  One  is  in 
connection  with  the  tillage  ami  rotation  experiments,  where  yield 
tests  of  cotton  are  being  made  mi  a  deep  fall  plowing  compared  with 
-hallow  fall  plowing,  deep  spring  plowing  compared  with  -hallow 
spring  plowing,  and  manured  land  compared  with  unmanured  land: 
also  drill  planting  compared  with  check-row  planting.  In  L907  deep 
plowing  yielded  better  than  shallow  plowing,  fall  plowing  better  than 
spring  plowing,  and  manured  land  about  the  same  a-  unmanured 
[Cir.  13] 


14  SAX    ANTONIO    EXPERIMENT    FARM. 

land.  Less  definite  results  were  obtained  from  the  comparison  of 
drilled  and  check-row  planting,  due  to  the  poorer  stand  obtained 
from  the  hill  planting,  which  was  done  by  hand. 

ACCLIMATIZATION    OF    WEEVIL-RESISTING    TYPES    OF    COTTON. 

Experiments  arc  being  made  with  a  considerable  series  of  the 
weevil-resisting  varieties  of  cotton  discovered  in  Central  America  by 
Mr.  O.  F.  Cook."  These  are  being  acclimatized  and  -elected  at  San 
Antonio  and  in  several  other  localities  in  Texas.  The  condition-  at 
San  Antonio  enable  the  new  varieties  to  display  their  drought-resist- 
ing qualities,  which  prove  to  be  unusually  high.  They  also  show,  in 
various  degrees,  the  characters  which  give  them  protection  against 
the  weevils. 

After  being  grown  for  two  years  at  San  Antonio  some  of  the 
varieties  remain  nearly  sterile,  but  others  are  rapidly  increasing  in 
fertility  and  have  already  overtaken  most  of  the  Upland  varieties 
included  in  the  test.  Special  attention  is  being  given  to  the  selection 
of  a  variety  of  cotton  suited  to  San  Antonio  conditions  by  combining 
as  much  as  possible  of  the  three  desirable  qualities  of  large  yield, 
weevil  resistance,  and  drought  resistance. 

HORTICULTURAL   WORK. 

Tests  are  being  made  of  the  varieties  of  grape-,  peaches,  Japanese 
persimmons,  apricots,  apples,  plums,  figs,  pistaches,  olives,  and  a  large 
number  of  new  fruits  and  ornamental  shrubs  and  trees  that  have  been 
introduced  by  the  Office  of  Seed  and  Plant  Introduction.  Altogether 
about  LO  acres  have  been  devoted  to  horticultural  work.  This  line  of 
work  is  of  very  great  importance,  for  the  tests  thus  far  made  indicate 
that  there  are  many  fruit  crops  well  suited  to  San  Antonio  condition-. 
The  fruit  trees  were  too  young  to  bear  in  L907,  but  most  of  them 
should  begin  bearing  in  the  near  future. 

Tree  crops  appear  to  be  more  especially  adapted  to  dry-land  cul- 
ture than  any  of  the  general  farm  crops,  because  the  trees  are  usually 
planted  far  apart  and  in  such  a  manner  as  to  permit  cultivation  of  the 
land  iii  two  directions.  Since  nearly  the  entire  surface  of  the  ground 
can  he  easily  kept  covered  with  a  dust  mulch,  the  loss  by  evaporation 
from  the  -oil  surface  i-  comparatively  -light.  Soil  moisture  deter- 
minations made  during  the  dry  months  of  1906  and  1907  showed  less 

""Weevil-Resisting  Adaptations  of  the  Cotton  Plant."  Bui.  SS,  Bureau  of 
I'l.-nit  Industry.  ''•  S.  Dept.  of  Agriculture. 

[Cir    i 


s\X     \\  I  (>\  h>    I  \n  1:1  VI  I  N  I     FARM.  15 

of  moisture  in  the  orchards  than  in  field--  planted  to  any  other 
crop. 

There  are  over  100  seedling  peache  on  the  farm  raised  from 
collected  in  one  oi  the  dry-land  fruit  regions  of  Mexico  by  Mr.  (i. 
Onderdonk,  of  Nursery,  Tex.  These  trees  have  been  making  rapid 
growth  and  are  bearing  fruit  for  the  first  time  this  season  (1908). 
[n  this  orchard  of  seedlings  it  is  hoped  thai  al  least  :i  few  trees  will 
be  found  thai  are  well  adapted  to  San  Antonio  conditions.  Any  trees 
that  prove  exceptionally  valuable  will  be  propagated  for  distribution. 

The  pistache  is  a  nut-producing  tree  quite  extensively  grown  in 
-.'me  parts  of  the  Old  World.  The  nut  i-  valuable  for  the  color  and 
pleasing  flavor  it  imparts  to  confections.  All  pistache  nuts  used  in 
the  I  nited  States  al  the  present  time  are  imported.  Several  hundred 
trees,  embracing  a  number  of  wild  species  brought  from  pari-  of 
Europe,  Asia,  and  Africa,  are  on  trial  at  the  experiment  farm.  They 
arc  hardy,  have  made  good  growth,  and  seem  to  -land  drought  well. 
This  work  with  the  pistache  is  conducted  in  cooperation  with  the 
Office  of  Plant  Life  Histon  [investigations  of  the  Bureau  of  Plant 
IihIii-'  i\ . 

CONCLUSIONS. 

In  tho  preceding  pages  the  chief  lines  of  work  under  way  at  the 
San  Antonio  Experinienl  Farm  have  been  outlined,  and  some  of  the 
results  obtained  in  L906  and  1907  have  been  given,  h  musl  be  borne 
in  mind,  however,  that  results  obtained  from  the  work  of  one  or  two 
year-  arc  hardly  sufficient  to  serve  as  a  basis  for  general  conclusions. 
Such  experiments  must  be  carried  on  for  several  seasons  and  be  sub- 
jected to  diverse  climatic  conditions  before  the  results  can  be  con- 
sidered reliable. 

The  chief  aim  of  this  circular  is  to  set  forth  -nine  of  the  agricul- 
tural problems  of  the  San  Antonio  region  and  t<>  show  how  the  solu- 
t  ion  of  these  problems  is  attempted. 

The  crop  year  of  1907  was  one  <>l'  low  rainfall,  the  total  precipita- 
tion for  the  vear  ended  September  1.  1907,  being  20.37  inches,  while 
the  normal  annual  rainfall  is  29.02  inches;  yet  the  yields  obtained  on 
the  experiment  farm  with  cotton,  sorghum,  and  corn  shovt  that  even  in 
the  driesl  seasons  fairly  good  crops  can  be  raised  when  the  best 
methoi  Is  of  i  illagc   i  re  l<  •!  low  ed. 

A  method  of  exterminating  Johnson  grass  has  been  practiced  suc- 
cessfully, and  the  cause  of  Ihe  failure  of  some  sorghum  varieties  to 
set  seed  in  this  section  lias  Keen  discovered. 

The  satisfactory  showing  made  by  many  of  the  varieties  of  fruit 
trees  under  trial  would  indicate  the  possibility  of  a  considerable  de- 

[Clr.  13] 


1Q  SAN    ANToNlo    EXPERIMENT    FARM. 

fcelopment  of  fruit  production  without  irrigation.  The  trees  are 
-till  very  young,  however,  and  many  difficulties  now  unforeseen  may 
develop  as  they  approach  maturity. 

Detailed  investigations  have  been  made  as  to  the  effectiveness  of 
various  tillage  methods  in  conserving  soil  moisture  and  as  to  the 
moist  me  requirements  of  various  crops. 

UNIVERSITY  OF   FLORIDA 


Approved : 

James  Wilson,  '"'TlS  0892^9549 ' 

Secretary  of  Agricultun  . 

Washington,  D.  C,  July  Hi.  1908. 

[Cir    13] 

O 


